Water Conservation and Management

Today’s Lecture

• Water pollution legislation• Increasing water supplies• Watershed management

Water Pollution Legislation• Federal Water Pollution Control Act (FWPCA) of 1972– Why was this needed? In the 1950s and 1960s:

• Potomac river too dirty to swim in• Cuyahoga River lit on fire• Lake Erie declared dead because of no deep oxygen

• Surface waters are classified by their designated uses– Drinking water, swimming and fishing, transportation and

agriculture

Do you think that different waters should be treated differently?

Water Pollution Legislation

• Minimal water-quality standards established• In 1977 FWPCA is amended and becomes the

Clean Water Act– All municipalities must have secondary sewage

treatment plants by 1988 (1987 amendment) • USGS monitors the water, and determined that

water quality hadn’t improved, and had possibly declined from 1991-1995. – Lead to an increase in attempts at controlling nonpoint

water pollution.

Water Pollution Legislation

• Safe Drinking Water Act (1974)– Protects the equality of drinking water– EPA is main regulator of drinking water quality• Website with EPA’s drinking water contaminants

What is happening in this picture?

Increasing Water Supplies

• Conservation• Reclamation of sewage water• Development of groundwater• Desalination of seawater• Rainmaking• Diversion of surface water to areas in need• Changes in crops that are engineered to

handle more saline water , or just less water

Increasing Water Supplies• Conservation

– On the farm• 40% of water is used for irrigation (USGS: http://ga.water.usgs.gov/edu/wuir.html)

• Reducing seepage losses– Water in irrigation ditches seeps out, also evaporates out

• Increasing drip irrigation– Less water loss by evaporation, only some crops suitable

• Heat and soil moisture sensors– More accurate way of determining when irrigation is necessary

– In industry• Increasing water costs

– Colleges and Homes• Installing water meters in every home• Reducing incentives to use excessive amounts of water

– Legal barriers• Changing legislative policies that hinder conservation• First in time, first in line and use it or lose it

Increasing Water Supplies• Effluent water is 99% pure and 1% polluted– May be cleaner than the stream water it is being

discharged into• Reclamation of sewage water– Gray water

• Water from sinks, showers, baths, and washing machines• Used for irrigation of golf courses• Used in industry as coolant water

– Black water• Water from toilets• Artificial wetlands created to treat this water before entering the

groundwater system

• Restrictions on water for irrigation of food crops

Increasing Water Supplies

• Developing Groundwater Resources– Less sustainable

• Drilling into new groundwater reservoirs will provide municipalities with ‘new’ water resources– Once they are depleted the municipality is back where

it started• Some solutions are to pump water back into the

groundwater system– Not completely efficient, may not all be recovered

Increasing Water Supplies

• Desalination– ~96% of the water on Earth is saline. • This water is not potable. Humans cannot drink it and

survive.

• Desalination plants remove the salt from the seawater, thereby making potable water.– Inefficient and expensive– Produces waste material (brine) that must be

disposed

Increasing Water Supplies

• Salt and Drought Resistant Crops– When soils become to salty as a result of a buildup

of chemicals and minerals in the soil it becomes poisonous to crops

– Development of crops that can survive in this soil would increase crop lands in the U.S. and abroad

• Crops that are genetically engineered to resist drought would be excellent candidates for diet staples in drought-common regions.

Increasing Water Supplies

• Rainmaking– Seeding clouds with silver iodide or sodium chloride

crystals into moist air.• The water condenses on the crystals and falls to the

earth as precipitation

• Unpredictable– Where it will fall– What the consequences of forcing rain are– What kind of ecological repercussions will there be?

Increasing Water Supplies

• Transporting water to areas in need• Example: California Water Project– Most of the water falls in northern California, but most

of it is needed in central and southern California.• The state implemented a $2 billion + project to

transport water• Criticism– Destruction of waterways– Excessive costs– Loss of scenic beauty

Figure 10.12 California Water Project. Major lakes and reservoirs are indicated by numbers. (C & R p. 238)

Watershed Management

• Manage entire watersheds– Reduce impervious surfaces, reduce nonpoint pollution

• Buffer zones– Create vegetated zones around streams and rivers to protect

from sediment runoff, and from organics and heavy metals• Educational programs

– Don’t wash cars on the street, don’t dump in stormdrains, pick up after pets

• PROBLEMS: all talk and no action– How can we improve watershed management plans so that

change is effected?

World View• Water pollution is a global issue• What are problems facing less-developed nations

dealing with water issues?Lack of funding – both individually and governmentally

Rampant warfare/feuding

Lack of education in the general public

Apathy

Lack of availability of water resources